Attachment for mining machine anchor jacks



June 3, 1952 Q BUTTRlCK 2,598,970

ATTACHMENT FOR MINING MACHINE ANCHOR JACKS Filed Feb. 17. 1949 l awe/who e zmes CLBuZZrz'c/t,

Patented June 3, 1952 UNITED STATES PATENT OFFICE ATTACHMENT FOR- MINING MACHINE ANCHOR JACKS 6 Claims.

My invention consists in new and useful improvements in an attachment for mining machine anchor jacks and relates more particularly to an improved anchor head adapted to be used in connection withjack pipes of the type generally employed in anchoring mining equipment during operation.

The primary object of my invention is to provide an anchor head which is designed to receive a conventional coal cutter bit for engagement with the mine roof, said head being so constructed that when being installed, the bit is positively forced into retaining engagement with the roof without the necessity of the machine operator cutting a hole in the roof to accommodate the jack pipepoint, which has been one of the objectionable features of anchor jacks ing angles of inclination of the jack body, so as,

at all times, to maintain the cutting end of the bit in position for substantially vertical engagement with the mine roof.

A further object of my invention is to provide an angularly adjustable bit having a novel, transversely retractable fulcrum arrangement, whereby the bit can be quickly released from engagement with the mine roof by the simple turning of one screw.

With the above and other objects in view which'will appear as the description proceeds, my invention consists in the novel features herein set forth, illustrated in the accompanying drawing and more particularly pointed out in the appended claims.

Referring to the drawing, in which numerals of like character designate similar parts throughout the several views:

Figure 1 is a view in side elevation partly broken away, showing my improved anchor jack in place in a mine;

Figure 2 is an enlarged sectional view through the anchor head showing" the bit in released position in full lines, and in engaging position dotted lines;

2 Figure 3 is a transverse sectional view taken on line 3-3 of Figure 2; and

Figure 4 is an enlarged detail of my improved bit fulcrum screw.

In the drawing, the numeral 5 represents a conventional jack pipe or anchor jack, adapted to be interposed between the roof 6 and floor I of an operation area in a mine, the lower end 8 of the jack pipe being sharpened for engagement with the floor 1. The upper end of the jack pipe 5 is adapted to receive the stem 9 of my improved anchor head II] which supports the coal bit II for engagement with the mine roof 6, as will hereinafter appear.

The head Ill and its dependent stem 9 are integrally formed preferably of solid steel, the head being sufficiently enlarged to provide adequate strength for the performance of its functions. As shown more clearly in Figs. 1 and 2. the head I0 is preferably shaped with an inclined face i2 through which a recess I3 is cut into the head, said recess terminating in an arcuate bottom or floor I4 and being substantially fan shaped in cross section. The bit H rests loosely in the recess 13 with its inner end normally engaging the arcuate floor I4 and its outer end projecting through the opening I5 in face l2, which forms the mouth of the recess I3. v

The bit ll may be a conventional coal bit, the cutting end 16 of which is preferably tipped with stellite and turned upwardly at an angle,

as will be seen from Fig. 2, said tip being sharpened for engagement with the roof 4 of the mine. The under side of the bit is fulcrumed on a screw or pin I! which extends transversely through the head III with the central portion of its shank lying across the recess l3, adjacent the mouth l5. One side of the periphery of this central portion of the shank of screw I1 is recessed as at l8 to receive the under side of the bit II, and the shank is screw threaded to engage complementary threads in the head 10. .Thus, the screw may be turned in the head to bring the recess l8 into and out of registry with the under side of the bit H for the purpose hereinafter set forth. r

The top face of the head [0 is provided with a boss [9 which is drilled and threaded to receive a threaded adjusting screw 20 which is preferably disposed at substantially right angles to the bit H in the recess 13 and is of sufiicient length for its inner end 20a, to cperatively engage the lower portion of the bit'at a point below the fulcrum pin l1. Thus, by adjusting the position of the screw 20 the angular disposition of the bit I I may be varied on its fulcrum.

If desired, I may provide an auxiliary set screw 2| which extends throughone of the side walls of'the head It and projects into recess [3 for engagement with the side of the bit ll. purpose of this auxiliary set screw is to retain the bit in place when the device is not in use and, as will later appear, to facilitate the longitudinal or outward adjustment of the bit under certain conditions.

In operation, the jack pipe 5 with my improved anchor head [0 in place, is installed for its usual The V purpose, between the floor and ceiling of an' operation area in a mine with the point 8 engaging the floor and the cutting end It of the bit I l engaging the roof 6. In order to insure the proper vertical direction of the cutting end, It in its engagement with the-roof 6, the relative angular position of the bit I I, with respect to the body of the jac pip is adjusted by rocking the bit on its fulcrum 11 through adjustment of the 'screw 20. When the bit is being set, the fulcrum pin ll is turned to a position with the non-recessed, 'cylindricalportion of its shank in engage- 'rn 'ent with the under side 'Of the bit H and this positionof thepin I? is'm'aintaine-d during the entire period of engagement of the bit with the "roof of the mine. 7

By turning the screw 2'0 inwardly, its iimer end a abuts the lower portion of the bit, rocking the latter on itsj fulcrum H, the leverage thus created, positively forcing the cutting end It into the roof Got the mine, to an effective depth diagrammatically illustrated by the line 117+.I3 in Figure 2'. This avoids the necessity of the operator cutting a hol'e'in the roof "of the mine to receive the bit. Obviously, if the height of the roof 6 with respect to the floor 1;, is such as to. require a more acute angle in positioning the jack pipe 5, this maybe compensated for by adjusting the screw 20 in the head I!) to cause the 'utting end [def the bit, to assume asub- 'stantially vertical line of engagement with the roof '6, the engagement being maintained so long as the screw 'Ztabuts the upper side of the bit I I.

When it is desired to release -the anchor jack,

thesimple turning of the fulcrum pin IT, to

condition's it may 'be necessary to extend the bit H longitudinally outwardly and in this event the set screw 2! cooperates with the adjusting screw 20 to retain the bit in its projected position. However, under normal conditions and for assuring the greatest degree of support, the lower end of the bit ll rides in engagement with the arcuate floor M of the recess l3.

It will thus be seen that I have provided a practical and eflicient anchor head which is simple in construction, easy to install and positive in its action. Furthermore, by the use of this device many of the hazards heretofore encountered in connection with conventional mining.

jacks are eliminated. For example, it is known that methane gas often collects in crevices in the roof of a coal mine and the digging of a hole in the sandstone roof of a mine with a pick as is necessary with the conventional type of jack, is likely to cause sparks which will result in an explosion from the, accumulated methane gas. Obviously this hazard is avoided by the use of my device which as before stated, eliminates the necessity of digging a hole in the mine roof.

From the foregoing it is believed that my invention may be readily understood by those skilled in the art without further description. it being borne in mind that numerous changes may be made in the details of construction without departing from the spirit of the invention as set forth in the following claims.

I claim:

1. In a mining machine anchor jack, including an elongated body having means at one end for engaging one of two vertically spaced mine surfaces; an anchor head carried at the opposite end of said body andv having a, bit-receiving "cavity, opening to the exterior adjacent the upper portion of said head, a bit loosely mounted in said cavity with its cutting end protruding through said opening, a transverse fulcrum for said bit, and an adjustable abutment extending into said cavity for engagement with said bit at a point below itsfulcrum, to regulate the angle of presentation or said bit to. the adjacent mine surface.

2. In a mining machine anchor jack, including an elongated body having means at one end. for engaging one or two vertically spaced mine surfaces; an anchor head carried at the opposite end of said body and having a bit-receiving cavity, opening to the exterior adjacent the upper portion of said head, a bit loosely mounted in said cavity with its cutting end protruding through said opening, a transverse fulcrum for said bit, and an adjustable abutment extending into said cavityrfor engagement with said bit at a point below its fulcrum, to-regulatethe angle of presentation ofv said bit. to the adjacent mine surface, said fulcrum being transverselyretractable to release the engagement of said bit with said mine surface. t r

end of said body, said head-having a bit-receiving cavity, opening to the extericradja-cent the upper portion of the head, arbit disposed said cavity with its cutting end protrudingthrough said opening, a transverse fulcrum member in said cavity for said bit, and adjustable means extending into said cavity, operauveiy engaging said bit at a point below its ruler-urn tor rocking said bit to regulate the penetrating engagement of its cutting end with the adjacent mine surface, said fulcrum being adjustable for varying its effective axis.

5. In a mining machine anchor jack, including 5 an elongated body having means at one end for engaging one of two vertically spaced mine surfaces; an anchor head carried at the opposite end of said body, a bit-receiving cavity in said head having an opening to the exterior adjacent the upper portion of the head, said cavity having substantially parallel side walls connected by end walls which diverge from said opening, a bit having one end loosely mounted in said cavity for movement between said diverging end walls and having an upturned cutting end protruding through said opening, a transverse fulcrum in said cavity for said bit, adjacent said opening, and an adjustable abutment extending into said cavity for engagement with said bit .at a point below its fulcrum, to regulate the angle of presentation of the cutting end of said bit to the adjacent mine surface, said fulcrum being transversely retractable to release said engagement with the mine surface.

6. A mining machine anchor jack as claimed REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 776,881 Ambrose Dec. 6, 1904 1,161,097 Williams et al Nov. 23, 1915 1,439,677 Holmes Dec. 19, 1922 1,783,290 Hulshizer Dec. 2, 1930 1,937,547 Cartlidge Dec. 5, 1933 2,084,925 Staten June 22, 1937 

